I will not say the opposite, but I keep on smiling because it's almost the configuration that I use (with a pair of 2" bipolar compression drivers). Of course, it's not a Doctor's replica, but gets interesting when considering the low distorsion and power handling.
There's a good resolution and some dynamic possibilities but it's not for nearfield listening. BTW, on my system, it disappears too in the space.
But he didn't invent it. I built my 1st MTM in 1975 and i got the idea from elsewhere.
The paper is on what is known as a d'Appolito configuration, which is an MTM with a specific XO configuration.
dave
Hello,
I suppose that a search of the press and technical papers will show when the term “MTM” came into use. I doubt that in 1975 a verticial array of midrange tweeter and midrange was called “MTM”. My reference to the good doctor included discussion of vertical lobeing and magical crossover. I doubt that symmetrical vertical lobeing and third order crossovers were part of the discussion in 1975.
DT
All just for fun!
I suppose that a search of the press and technical papers will show when the term “MTM” came into use. I doubt that in 1975 a verticial array of midrange tweeter and midrange was called “MTM”. My reference to the good doctor included discussion of vertical lobeing and magical crossover. I doubt that symmetrical vertical lobeing and third order crossovers were part of the discussion in 1975.
DT
All just for fun!
Hi,
By definition the symmetrical MTM arrangement will have symmetrical vertical
lobing whatever you do to the crossover. Nevertheless for the same tweeter
c/o point an MT will have less lobing in practice, though its not symmetrical.
There is a penchant for mega buck speakers to be vertically symmetrical
around a tweeter, with two mids, two basses etc, it is an approach.
But IMO in a domestic or studio environment I cannot sensibly see the
very expensive ATC dome midrange needing to be doubled up, and
I've never seen it used this way in designs that have used it.
If two are wanted for higher sensitivity and power handling, this puts
some severe constraints on the tweeter. For high power handling you
raise the c/o frequency of the tweeter. For doubled up midranges in
an ideal world you would drop the c/o point by an octave, this
does not happen, so you get more lobing at the c/o point.
You can double it up, But IMO there is no good reason to.
rgds, sreten.
By definition the symmetrical MTM arrangement will have symmetrical vertical
lobing whatever you do to the crossover. Nevertheless for the same tweeter
c/o point an MT will have less lobing in practice, though its not symmetrical.
There is a penchant for mega buck speakers to be vertically symmetrical
around a tweeter, with two mids, two basses etc, it is an approach.
But IMO in a domestic or studio environment I cannot sensibly see the
very expensive ATC dome midrange needing to be doubled up, and
I've never seen it used this way in designs that have used it.
If two are wanted for higher sensitivity and power handling, this puts
some severe constraints on the tweeter. For high power handling you
raise the c/o frequency of the tweeter. For doubled up midranges in
an ideal world you would drop the c/o point by an octave, this
does not happen, so you get more lobing at the c/o point.
You can double it up, But IMO there is no good reason to.
rgds, sreten.
sreten, you are right, and you even forget one more drawback : with this kind of driver (ATC or worse, ferrite 2" Cd) the magnet is much bigger than the emitting dome, then the tweeter and mids will be too much spaced and bye bye all good doctor implementation.
If we look at these data from "Oh no, he's back !", the ATC is not a good candidate over 4500 Hz, so as you say also, the tweeter will have to be good in front of these two mids.
OTOH, the distorsion peak around 350 Hz will be halved, allowing to go very low.
It's not rational, but IMO it's something that can be tried.
If we look at these data from "Oh no, he's back !", the ATC is not a good candidate over 4500 Hz, so as you say also, the tweeter will have to be good in front of these two mids.
OTOH, the distorsion peak around 350 Hz will be halved, allowing to go very low.
It's not rational, but IMO it's something that can be tried.
Hi, that was the original question, not I have 4 and can I use MTM, rgds, sreten.
e.g. it is used here : http://zaphaudio.com/SB12.3/ for sensitivity reasons.
And that is the typical case, when you have low sensitivity bass/mid drivers.
The ATC dome does not have sensitivity issues in most designs.
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I will only use them if it makes logical sense .
IF not worth the design ( that looks like its the case )
I will use the other pair for another system
There is never enough speakers at home ha ha !!!!
Distortion is lower I think and more output BUT since I am using an active system its not an issue here .
I think the single point source is a good point too YES .
I like the PMC s idea with dual 15 Volts s for extra energy in the room.
cheers
IF not worth the design ( that looks like its the case )
I will use the other pair for another system
There is never enough speakers at home ha ha !!!!
Distortion is lower I think and more output BUT since I am using an active system its not an issue here .
I think the single point source is a good point too YES .
I like the PMC s idea with dual 15 Volts s for extra energy in the room.
cheers
Unless you already got those tweeters they might be hard to get hold of since Dynaudio stopped selling bare drivers.
According to Zaphs tweeter test Hiquphon, Peerless or SB Acoustics appear to be possible choices.
Argghhh ! With the stock of great drivers you have (Focal, Atc, Esotar...) you can with no risk run any kind of test. Just use a temporary modular panel and not the top notch artwork.
Let your imagination take the wheel, the DIY fact is not an industrial process with price constraints. Then up to you to decide if it's better or not.
Let your imagination take the wheel, the DIY fact is not an industrial process with price constraints. Then up to you to decide if it's better or not.
one driver for each passband is easier
thus usually gives the best result
it might not sound very 'impressive'
but instead more homogene, more natural sound
even just two woofers can be a bit distracting
MTM with ATC can sound quite 'impressive'
but I also found it a bit 'annoying'
personally I prefer a more natural and less 'impressive' sound
but its your speaker, and your choise
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